Self starting, single-phase, single-coil induction and synchronous motor

ABSTRACT

The rotor may comprise a solid conductive disc, a slotted conductive disc, a conductive disc with a plurality of iron cores or permanent magnets equally spaced within the perimeter of said disc. The stator is a solenoid with an iron core and two iron arms , parallel to each other, positioned above and below the rotor; the arms forming an almost complete circle within and following the perimeter of the rotor. An AC field, originating within the solenoid, travels to the end of the solenoid&#39;&#39;s core arms. The flux lines are parallel to the rotor shaft and set up an apposing field within the conductive rotor causing it to rotate. Poles within the rotor sync with the ends of the core arms.

United States Patent [191 Alth [ SELF STARTING, SINGLE-PHASE,

SINGLE-COIL INDUCTION AND SYNCHRONOUS MOTOR [76] Inventor: Max Alth, 6Tamarack Rd., Port Chester, N.Y.

[22] Filed: Feb. 25, 1972 [21] Appl. No.: 229,265

[52] US. Cl. 310/163, 310/268 [51] Int. Cl. H021: 19/14 [58] Field ofSearch ..310/162-l64, 166, 156, 254, 259, 218, 193, 268

[5 6] References Cited UNITED STATES PATENTS 2,118,757 5/1938 Bergstrom310/166 1,668,365 5/1928 Hall 310/163 2,378,556 6/1945 .leffers 310/268UX 2,993,159 7/1961 DeVol 310/268 X R23,l55 10/1949 Warren 310/163 Aug.14, 1973 2,187,180 1/1940 Schweitzer, Jr 310/163 630,333 8/1899Dietrichfl 310/164 X 2,020,090 11/1935 Weed 310/163 X PrimaryExaminer--D. F. Duggan [5 7] ABSTRACT The rotor may comprise a solidconductive disc, a slotted conductive disc, a conductive disc with aplurality of iron cores or permanent magnets equally spaced within theperimeter of said disc.

The stator is a solenoid with an iron core and two iron arms parallel toeach other, positioned above and below the rotor; the arms forming analmost complete circle within and following the perimeter of the rotor.

An AC field, originating'within the solenoid, travels to the end of thesolenoids core arms. The flux lines are parallel to the rotor shaft andset up an apposing field within the conductive rotor causing ittorotate. Poles within the rotor sync with the ends of the core arms.

a 10 Claims, 6 Drawing Figures SELF STARTING, SINGLE-PHASE, SINGLE-COILINDUCTION AND SYNCHRONOUS MOTOR BACKGROUND TO PRESENT DISCLOSUREImproved alternator 04/02/70 251 l 17 Group 214 abandoned.

ADVANTAGES OF PRESENT INVENTION The present invention is an improvementover the self-starting, single-phase induction-synchronous motordisclosed by this applicant 01/11/71, Ser. No. 105 380, Group 212, forwhich all claims have been granted but no patent number has beenassigned at this writing.

The present motor (and the one that precedes it) differs from all othersingle-phase induction motors and single-phase synchronous motors inthat it has but one coil. There are no shorted-turn shading poles, thereis no split-phase winding with its attendant starting capacitor andstarting (throw -out) switch. The motor herewith described, starts as aninduction motor and upon attaining synchronous speed, locks into or withline frequency. Overloading does not stall the motor; it merely slowsand adjusts to the load.

The present motor is suited to loads ranging from flea power clocks) toseveral horse power. Larger motors can be constructed by using severalcoils, and multiphase currents can be accomodated by using severalcoils.

FIG. 1 is a plan view of the basic motor FIG. 2 is a cut-away view ofFIG. 1

FIG. 3 is a two-coil arrangement of the same motor FIG. 4 is a slottedrotor FIG. 5 is a rotor with laminated iron cores FIG. 6 is a solid,conductive disc rotor.

PRINCIPLE OF OPERATION When an electric current is led through asolenoid wound on an iron core and said core ends are bent to form along air gap, magnetic flux originates at the coil and moves outwarduntil it reaches the end of the core ends. When a conductor is placedwithin said air gap, AC flux movement tends to drive the conductor awayfrom the coil and towards the ends of the air gap. If the conductor isformed in the shape of a plate of metal, a stronger counter current isgenerated within the conductor and the effective force driving it out ofthe air gap becomes greater. If an iron rod is inserted orthagonal tothe plate; the iron forms the core of a transformer secondary and theinduced current is considerably increased.

In the present invention the AC flux is directed by the two long arms ofthe solenoid's core to travel around the circumference of a conductivedisc. Thus each iron core is a small transformer secondary core andremains within the AC field for most of its journey around the center ofthe disc. Consider the motor coil the primary of a transformer, considereach iron core as the second leg of the same transformer and theconductive metal surrounding it as the secondary winding.

Synchronization occurs at the AC voltage zero point and a rotor corepositioned approximately at the end of the pole arms. Sync speed at 60Hertz would be divided by the number of cores in the rotor or slots.

Referring to FIG. 1, which is a plan view of the basic, improved motor,The shaft is shown by 2, 3 indicates where a bearing member might bepositioned, 4 is a pole arm, 5 is the conductive rotor, 6 is a permanentmagnet, one of many similarly positioned and equally spaced about thecircumference of the conductive disc 5. 7 is the stator coil whichenergizes the poles 4 and 4.

Referring to FIG. 2; the same numerals are used. Again 2 is the shaft, 4is a pole, 6 is a permanent magnet, 5 is the conductive rotor and 7 isthe stator coil.-

When 7 is energized by an AC current, AC flux is propagated from thecoil, across the air gap between the two pole arms 4 and 4 until itreaches the ends of the gap and poles. As can be seen in FIG. 2, PM 6 ora soft iron core) is effectively surrounded by a conductive coil, i.e.,the metal of rotor disc 5. As can be realized,a repulsion current isinduced in this low resistance circuit and the core 6 is driven away andin doing so, causes the rotor to turn.

The basic difference between this disclosure and the previous motor isthe generally question mark shape of the poles. The cores 6 remainwithin the AC field for a considerably longer portion of the time. FIG.3 illustrates the approach that is taken for a multihorsepower motor ora motor witha large circumference rotor. This would be a design choicewhen high torque was desired. 11 is the shaft, l2.is the rotor, 13 oneof a plurality of iron cores, or any magnetically permeable material, 16and 17 are the stator coils and 14 and 15 are pole arms. The other polearms being invisible from this view point.

The stator coils may be connected in series or parallel.

This arrangement could also be used for two-phase current, and threesuch pole arrangements could be used for three-phase. However, thebenefit of two and three pairs of poles do not offset their complexityuntil the magnetic reluctance of the pole arms becomes inordinatelygreat clue to a very large rotor diameter.

As shown, solenoid core and pole arms are best made of laminated,magnetically permeable material. However, for low cost, low efficiencymotors, the core and poles can be cast iron. Rotor can be aluminum orcopper or any other electrically conductive material.

FIG. 4 is a slotted rotor providing some degree of synchronization andis useful for clock motors.

FIG. 5 shows the use of laminations for rotor cores or rotor poles.

FIG. 6 shows a solid conductive disc rotor which would have no tendencyto synchronize with line frequency but would find a rotational speedrelating power input to load.

Having described my invention and its manner of manufacture, this iswhat 1 claim as new and novel and desire to secure by Letters Patent:

1. A single-phase motor comprising an electrically conductive means,generally circular in outline and fastened to a shaft meanspassingorthogonally through its 3 center, a plurality of magneticallysusceptible core means piercing said conductive means, said coresgenerally positioned a distance inward from edge of said conductivemeans and generally equidistant from each other and generally circularabout said shaft means, said core means surrounded by conductive meanscooperating with magnetic flux to provide rotation and synchronization;said flux generated by a solenoid having a magnetically permeable coreterminating in two long arms parallel to each other and forming analmost complete circle within which said conductive means is positionedand free to rotate by. virtue of bearing means.

'2. A device as claimed in claim 1 wherein said electrically conductivemeans comprises a single disc of electrically conductive metal.

3. A device as claimed in claim 1 wherein said electrically conductivemeans comprises a single disc of electrically conductive metal, aplurality of permanent magnets, their magnetic axis parallel with saidshaft means, said magnets circumferentially disposed, equidistant fromone another about center of said electrical conductive means ,i.e., therotor.

4. A device as claimed in claim 1 wherein said electrically conductivemeans comprises a single disc of electrically conductive metal, aplurality of iron cores circumferentially disposed, equidistant from oneanother about center of said electrical conductive means.

5. A device as claimed in claim 1 wherein said electrically conductivemeans comprises a single disc of electrically conductive metalaplurality of laminated iron cores circumferentially disposed,equidistant from one another about center of said electrical conductivemeans.

6. A device as claimed in claim 1 wherein said solenoid core and armsare of cast magnetically permeable material.

7. A device as claimed in claim 1 wherein said solenoid core and armsare of laminated magnetically permeable metal.

8. A device as claimed in claim 1 wherein said electrically conductivemeans comprises a single disc of electrically conductive metal radiallyslotted a plurality of times, each slot generally equidistant from eachother, each slot originating a distance from said conductive meanscenter and-extending completely to its circumference.

9. A device as claimed in claim 1 wherein a plurality of solenoids andassociate core arms are used, said core arms sharing the circumferenceof the conductive means, less space between ends of said arms andsolenoid origins.

10. A device as claimed in claim 1 wherein a plurality of solenoids andassociate core arms are to be used, said core arms sharing thecircumference of the conductive means, less space between said arms andsolenoid origins, said solenoids to be connected to multiphase currentin an accepted manner.

3 I III k 8

1. A single-phase motor comprising an electrically conductive means,generally circular in outline and fastened to a shaft means passingorthogonally through its center, a plurality of magnetically susceptiblecore means piercing said conductive means, said cores generallypositioned a distance inward from edge of said conductive means andgenerally equidistant from each other and generally circular abOut saidshaft means, said core means surrounded by conductive means cooperatingwith magnetic flux to provide rotation and synchronization; said fluxgenerated by a solenoid having a magnetically permeable core terminatingin two long arms parallel to each other and forming an almost completecircle within which said conductive means is positioned and free torotate by virtue of bearing means.
 2. A device as claimed in claim 1wherein said electrically conductive means comprises a single disc ofelectrically conductive metal.
 3. A device as claimed in claim 1 whereinsaid electrically conductive means comprises a single disc ofelectrically conductive metal, a plurality of permanent magnets, theirmagnetic axis parallel with said shaft means, said magnetscircumferentially disposed, equidistant from one another about center ofsaid electrical conductive means ,i.e., the rotor.
 4. A device asclaimed in claim 1 wherein said electrically conductive means comprisesa single disc of electrically conductive metal, a plurality of ironcores circumferentially disposed, equidistant from one another aboutcenter of said electrical conductive means.
 5. A device as claimed inclaim 1 wherein said electrically conductive means comprises a singledisc of electrically conductive metal a plurality of laminated ironcores circumferentially disposed, equidistant from one another aboutcenter of said electrical conductive means.
 6. A device as claimed inclaim 1 wherein said solenoid core and arms are of cast magneticallypermeable material.
 7. A device as claimed in claim 1 wherein saidsolenoid core and arms are of laminated magnetically permeable metal. 8.A device as claimed in claim 1 wherein said electrically conductivemeans comprises a single disc of electrically conductive metal radiallyslotted a plurality of times, each slot generally equidistant from eachother, each slot originating a distance from said conductive means''center and extending completely to its circumference.
 9. A device asclaimed in claim 1 wherein a plurality of solenoids and associate corearms are used, said core arms sharing the circumference of theconductive means, less space between ends of said arms and solenoidorigins.
 10. A device as claimed in claim 1 wherein a plurality ofsolenoids and associate core arms are to be used, said core arms sharingthe circumference of the conductive means, less space between said armsand solenoid origins, said solenoids to be connected to multi-phasecurrent in an accepted manner.